Root Gap – X – “Space” for welding the O’let is raised off the run pipe to establish proper weld gap by placing spacers, e.g. welding rods, under the fitting. This provides a uniform welding gap between the curvature of the run and base of fitting.

Threaded Ends are in accordance with ASME B1.20.1. Design per MSS SP-97.

Source comes from Bonney Forge (except the sizes in millimeters).

Thredolet® is a registered name. Another often used name is Threaded Outlet.